Spotting at 8dpo

Soooo hello ladies!

First time poster, and recent user of this app.

Anyway! The reason I'm here is, I had some spotting at 8dpo and I hit automatically assumed I was pregnant - I have a 3yo and a 7mo so it would be a surprise but not unwelcome.

However I keep getting negative results. Period is due tomorrow and I don't know if I feel pregnant or anything...

But if I'm not... why on earth would I spot? I never EVER bleed in between periods. EVER. So I'm very confused.

Any advice/info welcome!